The latest edition of Journal Citation Reports containing impact factors for 2015 has just been released. On campus you can access it from https://jcr.incites.thomsonreuters.com/ . If you need to use it off campus go to iFind and search for Incites Journal Citation Reports. This should take you to a point where you can use your Swansea University login.

Note that the database only covers science and social science although a few journals from other areas may have an impact factor.

If you want to look at the current ranking of journals within a subject area

go to Categories by Rank.

Click on the number which you can see in the Journals column in the image below. This will give you a listing of journals ranked by impact factor.

There is a check box at the left of the screen which you can use if you want to find open access journals with a good impact factor.

If you want more information on the different statistics available from JCR their guide is a good starting point.